Platen leveling multiple ram press



Aug. 28, 1951 G. A. WALDlE PLATEN LEVELING MULTIPLE RAM PRESS 3Sheets-Sheet 1 Filed Jan. 22, 1945 z MIT 2W N 5 5. 5 w #5 4 3 am J N) l/l 5 T N v o NA R 9 I r v M 4 WE k V 5 mm m 7 2 8 b $11M. w. w Aw 4 ,.p k/QJ G J 2 x M ma 4 m 4). 5

0 2/532 1. 7 6 9 3 3 3 W M m "J u 6 JV 7 Q P 6 I MM w 2 w m 2 5 5 1 a oo o 3 5 mm 38 FL 2 I o m y 7 z a 6 L u E m m I II I I 5 3 m. I g. u/u- 1FD J w. MM m R Aug. 28, 1951 v v I G. A. WALDIE 2,565,639

PLATEN LEVELING MULTIPLE RAM PRESS Filed Jan. 22, 1945 s Sheets-Sheet 2INVENTOR, GEO/7G5 14 WALD/E ATTORNEYS 1951 v G. A. WALDIE I 2,565,639

I PLATEN LEVELING MULTIPLE RAM PRESS Filed Jan. 22, 1945 5 Sheets-Sheet5 iNVENTOR GEORGE A. WALD/E oni; A'JMLML.

ATTORNEYS Patented Aug. 28, 1951 PLATEN LEVELING MULTIPLE RAM PRESSGeorge A. Waldie, South Woodbury, Ohio, as-

signor to H-P-M Development Corporation, Wilmington, DeL, a corporationof Delaware Application January 22, 1945, Serial No. 574,013

11 Claims. 1

This invention relates to hydraulic mechanisms and machines andparticularly to the correction of deflections of the pressing member asin platen of hydraulic presses in which deflections may occur during thepressing operation.

In particular, it is the object of this invention to provide anelectrical control system for regulating the application of hydraulicpressure on a multiplicity of hydraulically actuated platen actuatingmembers so as instantaneously to detect any inequalities in the pressingoperation.

It is an object to provide an artificial horizon, the floating movementsof which control the electrical circuits which in turn control thehydraulic circuits for the correction hydraulically of the platenmovements.

It is a further object to provide mechanism in which a plurality offluid power sources supplying hydraulic pressure to a plurality ofplaten actuating plungers or pistons are electrically controlled by themovement of the horizon bar and the hori= zon bar is hydraulicallyactuated.

In particular, it is the object of this invention to provide anelectrical operating mechanism which depends for its actuation upon thecondi tion of magnetic fields thereby eliminating any frictional factorsor delays due to inertia in hydraulic circuits in connection with thecontrol of hydraulic circuits that in turn convey fluid to actuate theplaten.

It is a further object to provide electrically actuated valves whichthemselves have no Work to do and, therefore, have the minimum ofinertia and time lag as well as waste of power, with the consequencethat the only mechanism involved is the hydraulic circuit directlyconnected to the platen actuators thereby increasing the speed ofreaction and sensitivity of the controls.

Referring to the drawings Figure 1 is a side elevation, partially insection, of a press head, platen and platen actuating mechanism togetherwith the electrical and hy draulic circuits and pump mechanism showndiagrammatically. This view illustrates all of the essential elements ofthe invention;

FigureZ is a diagrammatic view of the electrical and valve actuatingmechanism;

Figure 3 is a section over the platen of a press having a plurality ofactuating rams;

Figure 4 is a diagrammatic view of the electrical, hydraulic andmechanical arrangements of a press head, platen and control mechanismshowing a modification by which the artificial horizon bar is fluidactuated.

Referring to the drawings, l indicates the reversible fluid pump adaptedto deliver fluid to the cylinders 2 through the pipes 3 and 4, from themain line 5, to the under side of the pistons i of the platen plungers 8and, through the line 9 and valves I0 and H to the top of the cylinders2 above the pistons 1. The main line 5 is provided with a check valve 5awhich has its inlet side in communication with a fluid reservoir 5b andwhich opens only in the direction of the pump 1 to supply make up fluidto the system when fluid is being pumped through the line 9. Indicatedat l2 and I3 are standard type surge valves such as the type describedin United States Patent No. 1,956,758, dated May 1, 1934, to WalterErnst, for prefilling the cylinders 2 on the downward stroke of thepiston 1 and for evacuating the fluid above the piston '7 during theretraction stroke. These valves are connected by the pipes I4 and. I 5to the main pipe 5 and have internal movable valve members, not shown,which are operable in response to a predetermined pressure within themain pipe 5 to open the valves to permit fluid above the piston 1 to beexhausted.

The pump I is provided with a servo-motor I6 which has the piston rod I1extending from one end. This motor is used for reversing the pump andthe direction of flow through the pipes 5 and 9. The outer end of thepiston rod 11 is connected by the lever I8, which is pivotally supportedbythe link l9, to a pitman 20 which in turn is pivotally connected at 2|to a bell crank 22 pivoted at 23. One end of this bell crank isconnected to a solenoid core 24 operating within the coil 25 which inturn is connected to a source of electric power by the leads 26 and 21.The circuit thus formed is controlled by the switch 28. The other end ofthe bell crank lever 22 is engaged by the shift rod 29 having a collar30 which engages with the bell crank 22. This shift rod is provided witha collar 3| which is adapted to engage with the eye 32 mounted on thepress head 2a. The lower end of the shift rod 29 is provided with athird collar 33 which engages with an eye 34 on the platen 35. Thisplaten is provided with piston rods 8, each of which has a piston 11 onits upper end and such piston rods and pistons respectively travel inthe cylinders 2 in the head 2a.

Mounted in the press head 2a in spaced bearings 36 in the chamber 31 isthe floating shaft 38 which is rigidly joined at 39 to the bar 40 whichconstitutes an artificial horizon or deflector bar. The bar 40 iscarried upon the ball support 4|, upon which it can freely rock relativeto the plat en 35. This rocking support 4| is mounted on the 3 top ofthe platen 35 and may comprise hardened wear pads which tend also tominimize friction.

The outer ends of this bar carrying c shaped magnetic members having thearms 42 and 43 with inwardly turned heads 46. Mounted on the respectivearms of the magnetic structure are the coils 45 and 46, and between thearms is pivoted a core 47 as at 48. The outer end of this core isslotted at 49 to form a jaw riding upon a cross pin 50 mountedtransversely of the stud 5| which has spaced stop nuts 52 and 53 mountedthereon. This stud is mounted upon the upper surface of the platen 35.The deflector bar or floating horizon bar 40 is continuously urgedtoward the platen by the opposed springs 54 which are connected at theirrespective ends to the platen 35 and bar 40.

It will be apparent that the movement of the bar 40 with respect to theplaten 35 will move the core 41 relative to the arms 4-2 and 43 and willinfluence the coils 45 and 46 thereby varying the energization of theelectrical mechanism through the amplifier generally designated 55. Asthe result of such amplification the solenoid operated valves and H arerespectively actuated as hereinafter explained.

It will be observed that in all these relationships there is the minimumof physical engagements of parts so as to provide for the maximumsensitivity of the control and correction of the pressure upon theplaten or the retraction of a portion of the platen in order to maintainthe platen on an even plane.

Referring to Figure 2 which illustrates in detail the amplifier 55, thepower lines in which the amplifier is connected are designatedrespectively 56 and 57. The line contains a choke coil 58. The chokecoil 58 is connected with a line 59 to the coils 66 and 61. It proceedsthrough the wire 62 whence it is connected to the lines 63, 64respectively. The line 63 contains the resistances 65 and 66 and isconnected at 61 to the cross line 68 which in turn is connected to theline 56. The line 64 contains the resistances 63 and 70 and is in turnconnected with the line 68.

The other end of the coil 60 is connected by the wire H to the plate '53of the thyratron tube 12. The grid 14 is connected to the variableinductance 15, the free end of which is connected to the line 63 at 16,and the cathode 18 is connected to the wire 68. Connected across thevariable inductance line and the wire 68 is an adjustment forsensitivity consisting of the variable resistance I'I. The use of theadjustable or variable inductance permits oi varying the current fromzero to maximum.

There is a pair of such thyratron tubes 12, one of which is connected tothe coil 66 and the other to the coil 6|, the two coils being connectedtogether to form a single solenoid. The core operable within such coils6ll6l consists of a valve stem 19 having the core members 80 and BI. Thevalve stem 19 is in turn connected to the valve member 82 which isreciprocated within the valve H to control the passage of fluid throughthe line 9.

It will be understood that the coils 45 and 46 are the coils indicatedin Figure 2 within the variable inductance 15, as well as the coremember 47.

In operation, the thyratron tubes are equally effective in passingcurrent between the power lines 56 and 51 and through the coils 66 and6| when the variable inductances at 45 and 46 are equal. When theseinductances are varied by a .4 movement of the core 41 within the arms42, 43, there is a phase shift in each of the grid networks of thethyratron tubes such that one passes increased current and the otherdecreased current. This produces a thrust on one of the armatures 60,6|, to move the control rod 19 in one or the other direction. It will beapparent that the differential in current flow and, therefore, thethrust on the double armature combination, is in a direction andproportional to the deflection of the platen relative to the referencebar. The thyratron circuit is initially balanced by an adjustment of theresistors H and the sensitivity of the entire arrangement is alsoinfluenced by the setting of these resistors.

Referring to Figure 4, this modification relates to independent controlsdirectly connected to independent pumps which suppl or remove fluid totheir respective platen actuating cylinders to airect the pistons inthose cylinders. Figure 4 also relates to the use of a fluid actuatedreference bar or artificial horizon. In this manner, particularly inlarger size presses, great sensitivity is provided and additionallypositive and rapid action in responding to the sensitive controlsheretofore described which are individually applied to the pump andcylinder combination.

Referring to Figure 4, the control system is arranged as follows. Theshaft 238 has a relatively enlarged piston 83 working within thecylinder 31. The top and bottom of the cylinder are sealed with gasketsand retaining rings designated 84 and 85. The fluid chamber, thus formedbelow the piston 83, is supplied with fluid from the pump 86 through thepipe 8'! and the pipe 83 supplies fluid to the part of the cylinder 3?above the piston 33. This pump in turn is actuated so far as beingshifted to direct the fluid either through the pipe 81 or 88 through asolenoid core 89 working within the coil 96 and spring pressed in onedirection by the spring 9| mounted on the abutment 92. The coil 96 isconnected into an electrical circuit designated 63, 34 which iscontrolled by the switch 95.

The switch 95 can be closed in any desired manner whereupon an electriccircuit will be completed through the coil 90 which will draw thearmature 89 rightwardly against the thrust of the spring BI and positionthe pump 86 to deliver into the conduit 88 while withdrawing fluid fromthe conduit 81. This brings about a downward movement of the piston 83and bar 40a. After the work has been engaged and accomplished, theswitch may be opened in any suitable manner whereupon the spring 3 I iseffective to shift the core and armature 39 leftwardly to reverse thedelivery of the pump 86 to bring about its discharge into the conduit6'1 and the subsequent retracting movement of the piston 83 andreference bar 46a. It will be obvious that the switch 95 could beadapted for manual control.

At the conclusion of the cycle, the pump is brought to neutral by themovement of the bell crank 96 which in turn is actuated by the thrustrod 91 which engages with the floating horizon or reference bar 46a. orratio between the advancing and retracting areas of the piston 83 isequal to the differential or ratio of the same areas of the pistons I,and it will be noted that a surge valve 381) similar to the valves I2and I3 is connected to the upper end of the cylinder 31. Thus, the rod238 advances rapidly to working position and then proceeds at a reducedrate through the working Preferably, the diiferentialstroke. A spring38a is effective, when the platen 35 engages the work and slows down, tocheck the travel of the rod 238 thereby to cause the surge valve 38b toclose.

Coincident with these operations, the following operations take place inconnection with the movement of the platen 35 as theresult of themovement of the pistons I and piston rods 8 which are connected to theplaten. Thedownward movement of the reference bar 4011 through theaction of the pump 86 results in moving the core arm 41 in closerrelationship to the coil 45. The operation continues as heretoforedescribed except for the fact that the coils 60 and SI respectivelyembrace movable solenoid cores 60a and 60b which are pivotally connectedto the bell crank 98 which in turn is connected by the pitman 99 andlever I to the shift rod IOI of the servomotor I02 that controls thepump la. The lever I00 is pivoted on the link I03 to provide a movablefulcrum point for the lever action. This results in the pump Ia beingshifted so as to supply fluid through the pipe I04 to the top of thecylinder 6 above the piston I. The pipe I05 is withdrawing fluid frombeneath the piston I and returning it to the pump or withdrawing it fromthe sump tank I 06, by way of a check valve I06a, as the necessity mayarise. The descent of the platen serves to move the movable core member41 away from the coil 45 and ultimately close to the coil 45. When thisoccurs the pump is reversed by the action of the solenoid 6| on its core60!) so that fluid pressure is delivered through the pipe I05 and fluidis withdrawn through the pipe I04. The platen 35 will continuedownwardly until the switch 95 is manually opened. At that time thereference bar 40a will be moved upwardly and there will be acompletereversal of the pumps Ia and Ib. The controls for pump lb arethe same as for Ia but are not fully shown for the purpose of clarity.

There are, therefore, two primary stages to this operation: the movementdown of the platen 35 which is held in engagement with the work for thedesired period and the movement upwardly to the initial position; andthen the second movements which are those adjusting movements of theseveral pistons I in the head 2a of the press for constantly adjustingthe platen at its edges or corners to maintain it in a level condition.This is accomplished, as heretofore described, also through the samefluid suspended reference bar 40a and the adjustable solenoidsdesignated 75 each consisting of the two coils 45 and 46, their cores 42and 43 and the adjustable member 41 one end of which is pivoted on thereference bar and the other end of which is actuated by reason of itsslidable connection with the platen 35. The combination of the levelingmechanism and circuits with the hydraulically actuated reference barwhich performs the dual function of controlling, with its hydrauliccircuit, the main pump action for main movements and the action of themain pumps for effecting minor leveling movements. It is this conceptionthat is deemed unique. The advance in this construction shown in Figure4 over the previous views is in providing the hydraulically actuatedreference bar 40a which acts to both control the major movement of thepress as well as the minor leveling movements. This means that all ofthe pumps must act in synchronism in connection with the major movementsand the pumps must act in individual independent man- 6 1 ner inconnection with the levelingr'novements resulting from pump independentaction.

It will be understood that I desire to comprehend within my inventionsuch modifications as come within the scope of the claims and theinvention. c

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent is:

1. In a hydraulic press; a press platen; spaced movements therebetweenfor generating an elec-' trical signal in proportion to said relativemovement; and means continuously responsive to said electrical signalfor actuating said control means for restoring said platen to itsoriginal relative to said reference means.

2. In a hydraulic press; a reciprocable platen;

a reciprocable reference means movable bodily with said platen andconstrained to remain parallel to a predetermined position; electricalmeans carried by said reference means and responsive to relativemovement between said reference means and platen to generate a signalproportional to said relative movement; control means connected to beactuated in direct proportionlto said signal; and motor means connectedto drive said platen at spaced points and having the power theretocontrolled bysaid control means.

3. In a hydraulic press; a platen; spaced motor means connected withsaid platen; a reference means movable bodily with said platencomprising a bar constrained to remain parallel to a predeterminedposition; electrical means carried by said bar and platen and responsiveto relative movements therebetween to generate a signal in proportion tosaid relative movements; an amplifier for amplifying said signal;control means for controlling the relative supply of fluid to saidmotors; and electrical means operated by said amplified signal foractuating said control means to vary the supply of fluid to said motorsto maintain said platen and bar in a fixed relative position.

4. In a hydraulic press; a platen; a plurality of spaced plungers foractuating said platen; fluid pressure suppl means for supplyingactuating fluid to said plungers; electrical control means forcontrolling the supply of fluid to each of said plungers; referencemeans comprising a bar movable in the same direction as said platen andconstrained to remain parallel to a predetermined,

position; means for actuating said bar in reciprocating movementsindependently of said platen:

and means responsive to relative movements be tween said bar and platenfor actuating said electrical means to control the delivery of fluid tosaid plungers whereby said platen follows and remains parallel with saidbar.

5. In a hydraulic press; a main platen; an auxiliary platen movable inthe same direction as said main platen and constrained to remain-parallel in all positions; a plurality of spaced motor means foractuating said main platen; individual motor means for reciprocatingsaid auxiliary platen; and means responsive to relative movement betweensaid auxiliary and main platens position 7. for controlling the speed ofoperation or the motor means connected with said main platen formaintaining said main platen substantially parallel at all times.

6. In a hydraulic press; a reciprocable main platen; a plurality ofspaced plungers having advancing and retracting means connected withsaid main platen; fluid pressure supply means for supplying saidadvancing and retracting means; electrical means for controlling thesupply of fluid to said advancing and retracting means; an auxiliaryplaten movable in the same direction as said main platen and constrainedto remain parallel in all positions; auxiliary motor means for drivingsaid auxiliary platen in both directions of movement; and electricalmeans continuously and proportionately responsive to tilting movementsbetween said platens for controlling the supply of energy to saidelectrical control means whereby said main platen follows and remains infixed relationship with said aux iliary platen.

7. In combination in a hydraulic press; a plurality of actuating pistonsand piston rods and cylinders arranged at spaced intervals; a platenengaged by said piston rods; an artificial horizon bar moving with saidplaten, said platen being deflect-able with respect to said bar, theends or" said bar being located adjacent said piston rods; electricalmeans associated with the ends of said deflector bar and said platenwhereby any dofiection of the platen with respect to the bar willinstantaneously modify the condition of said electrical means; amplifiermeans to amplify the changes in said electrical means; and otherelectrical means continuously responsive to said amplified changes tobring about an application of hydraulic power to the associated pistonand piston rod adjacent the part of the platen which is. deflected.

8. In combination in a hydraulic press; a platen; hydraulic means formoving said platen arranged at spaced intervals thereon; an artificialhorizon bar movable with said platen, said platen being adapted todeflect without deflectingsaid bar; electrical means associated withsaid bar for instantaneously electrically signalling any deflection ofthe platen adjacent spaced points on said bar; means for amplifying saidsignals; and means continuously and, substantially instantaneouslyresponsive to said amplified signals for electrically actuating acontrol for the application of hydraulic pressure to said platen at thepoint of deflection to restore it to normal.

9. In combination in a hydraulic press; a platen; a source of fluidpower; hydralically actuated pistons and piston rods spaced on fourcorners of the platen; a reference bar movably mounted to move bodilywith said platen and having arms extending to the corners of the platenadjacent said piston rods; means on the ends of said arms forcontinuously signalling electrically the deflection of the portion ofthe 87 platen adjacent thereto, means for amplifying said signal; andmeans continuously responsive to said signal for electricallycontrolling the application of fluid pressure to the piston and pistonrod adjacent the deflection point of said platen to restore it to itsnormal position.

10. In combination in a hydraulic press; a platen; hydraulicallyactuated pistons and piston rods spaced on the four corners of saidplaten; a bar mounted to move bodily with said platen and having armsextending to the corners thereof adjacent said piston rods, means on theends of said arms for generating an electric signal in proportion to thedeflection of the portion of the platen adjacent thereto; means foramplifying said signal; means continuously responsive to the amplifiedsignal for controlling the application of fluid pressure to the pistonand piston rod adjacent the deflection point of said platen to restoreit to its normal position; and means of maintaining said bar inparallelism with its original position throughout a press cycle.

11. In combination; a platen; a plurality of spaced pistons and pistonrods for moving said platen, said piston rods engaging said platen,cylinders adapted to receive said pistons and piston rods; an artificialhorizon bar comprising radiating arms terminating adjacent the points ofengagement of the piston rods with said platen; means, moving saidartificial horizon bar independently of said platen; electrical means onthe ends of said arms comprising means for varying an electric currentupon and in proportion to the change of relationship of the adjacentportion of the platen with respect thereto; means for amplifying thechanges in electric current; and electrical means controlled by saidamplified changes adapted to vary the supply of fluid pressure to theadjacent piston and piston rod to vary the rate of travel of the platenwhether the platen is deflected towards or away from the adjacentportion of the artificial horizon bar.

GEORGE A. WALDIE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,296,051 Pocock etv a1. Sept.15, 1942 2,309,944 Flowers Feb. 2, 1943 2,312,213 Ferris Feb. 23, 19432,343,167 Bench Feb. 29, 1944 2,357,507 Ernst Sept. 5, 1944 2,357,508Ernst Sept. 5, 1944 2,377,007 Hess May 29, 1945 FOREIGN PATENTS NumberCountry Date 537,497 Germany Nov. 4, 1931 540,881 Germany Dec. 31, 1931

